p-(1,1-dimethylpropyl)phenol

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1988

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Peer review publication describing two acute inhalation studies that were performed following the basic principles of OECD guideline 433, but neither adherence to the guidelines nor GLP status is claimed.
1) Five male and five female rats were exposed to a saturated vapour of p-tert butyl phenol for 6 hours
2) Five male and five female rats were exposed to a dynamically generated dust aerosol for 4 hours.

GLP compliance:

no

Test type:

fixed concentration procedure

Test material

Test material information

Constituent 1

Reference substance name:

4-tert-butylphenol

EC Number:

202-679-0

EC Name:

4-tert-butylphenol

Cas Number:

98-54-4

Molecular formula:

C10H14O

IUPAC Name:

4-tert-butylphenol

Test material form:

solid: flakes

Details on test material:

- Name of test material (as cited in study report): p-tertiary butylphenol
- Molecular formula (if other than submission substance): C10H14O
- Molecular weight (if other than submission substance): 150.21 g/mol
- Physical state: solid white flakes
- Analytical purity: 99.9%

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Zivic Miller Laboratories inc, Zelionople, PA, USA and Harlan Sprague Dawley inc, Indianapolis, IN, USA.
- Weight at study initiation: 200-300 g
- Acclimation period: 5 days
- Photoperiod (hrs dark / hrs light): 12hr light and dark cycle

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: plexiglass chamber
- Exposure chamber volume: 120 litre
- Source and rate of air: filter compressed air carried dust into chamber
- System of generating particulates/aerosols: dust aerosols were generated by melting flakes in a flask at 110 degreesC
- Method of particle size determination: determined with a TSI model APS 3300 aerodynamic particle sizer
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): calculated by probit analysis.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

5600 mg/m^3 of PTBP dust aerosol

No. of animals per sex per dose:

5 males, 5 females.

Control animals:

not specified

Statistics:

None

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5 600 mg/m³ air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

1 male and 1 female rat died within 1 to 2 days, a mortality rate of 20%.

Clinical signs:

other: Clinical signs observed in this group of animals on the day of exposure and up to 7 days post-exposure included signs of mucosal irritation (perinasal, perioral, and periocular encrustation) and signs of respiratory distress (audible respiration, gasping

Body weight:

A loss of mean body weight was observed for both sexes on day 7, but body weight gains were exhibited by day 14.

Gross pathology:

Upon necropsy, dark red or purple discoloration of the lungs and/or kidneys was observed in the two rats that died, but no macroscopic lesions
were observed in rats that survived until study end.

Applicant's summary and conclusion

Interpretation of results:

sligthly toxic

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the high exposure conditions for 4hours, and despite the observed clinical signs, the material is not considered irritating to the respiratory tract (Decision based on RAC meeting, RAC/M/21/2012).
LC50 >5600 mg/m^3

Executive summary:

Under the high exposure conditions for 4 hours, the test item was not acutely toxic; LC50 >5600 mg/m^3.

Clinical signs of mucosal irritation (perinasal, perioral, and periocular encrustation) and signs of respiratory distress (audible respiration, gasping, and a decreased respiration rate) were observed, but could not be confirmed during histopathology. These findings are considered to reflect physical or mechanical effects triggered by the high dosage. Despite these findings p-tert-butylphenol is not classified as respiratory irritant based on the decision made by the Committee for Risk Assessment (2012, RAC/M/21/2012).